I did this many years back with my work's phone system and an unused DID. Pro-Tip: Make a phone tree. 1 calls your cell, 2 calls your roommates cell, and pres

I did this many years back with my work's phone system and an unused DID. Pro-Tip: Make a phone tree. 1 calls your cell, 2 calls your roommates cell, and pressing a secret key like 6 dials your 9 response.